Measurement While Drilling (MWD)

Definition - What does Measurement While Drilling (MWD) mean?

"Measurement while drilling" (MWD) refers to the real time data relayed to the drill operator during the drilling process. This helps engineers and operators to make critical decisions while drilling. The measuring instrument is installed in the drill head and is connected to the monitoring computer. It also ensures that the drill is taking the assigned path.

Any change in direction is immediately conveyed to the operator enabling them to do the necessary corrections. This application is very crucial in methods of trenchless construction because of the jumble of water, sewer and gas pipelines, TV and phone cables, etc. that crisscross underground. Cross bores can result in serious accidents.

Trenchlesspedia explains Measurement While Drilling (MWD)

MWD works by using magnetometers, gyroscopes and accelerometers that measures the azimuth and inclination of the borehole at a particular location and is transmitted to the surface. It also provides drill bit information, wellbore position and directional data. When a critical change in angle and direction takes place, MWD provides continuous updated measurements that can be used for making real time drilling adjustments.

Corrections can be made by adjusting drill string weight, rotation speed or introducing a downhole motor. Soil conditions that can damage the drilling equipment can also be ascertained and necessary steps can be taken. When the direction of the drill path changes untintentionally, this is called a deviation.